From: Freeman Liu <freeman.liu@xxxxxxxxxx>
The Spreadtrum eFuse controller is widely used to dump chip ID,
configuration setting, function select and so on, as well as
supporting one-time programming.
Signed-off-by: Freeman Liu <freeman.liu@xxxxxxxxxx>
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
---
drivers/nvmem/Kconfig | 11 ++
drivers/nvmem/Makefile | 2 +
drivers/nvmem/sprd-efuse.c | 424 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 437 insertions(+)
create mode 100644 drivers/nvmem/sprd-efuse.c
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index c2ec750..8fd425d 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -230,4 +230,15 @@ config NVMEM_ZYNQMP
If sure, say yes. If unsure, say no.
+config SPRD_EFUSE
+ tristate "Spreadtrum SoC eFuse Support"
+ depends on ARCH_SPRD || COMPILE_TEST
+ depends on HAS_IOMEM
+ help
+ This is a simple driver to dump specified values of Spreadtrum
+ SoCs from eFuse.
+
+ This driver can also be built as a module. If so, the module
+ will be called nvmem-sprd-efuse.
+
endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index e5c153d..7c19870 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -50,3 +50,5 @@ obj-$(CONFIG_SC27XX_EFUSE) += nvmem-sc27xx-efuse.o
nvmem-sc27xx-efuse-y := sc27xx-efuse.o
obj-$(CONFIG_NVMEM_ZYNQMP) += nvmem_zynqmp_nvmem.o
nvmem_zynqmp_nvmem-y := zynqmp_nvmem.o
+obj-$(CONFIG_SPRD_EFUSE) += nvmem_sprd_efuse.o
+nvmem_sprd_efuse-y := sprd-efuse.o
diff --git a/drivers/nvmem/sprd-efuse.c b/drivers/nvmem/sprd-efuse.c
new file mode 100644
index 0000000..2f1e0fb
--- /dev/null
+++ b/drivers/nvmem/sprd-efuse.c
@@ -0,0 +1,424 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2019 Spreadtrum Communications Inc.
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/hwspinlock.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+#define SPRD_EFUSE_ENABLE 0x20
+#define SPRD_EFUSE_ERR_FLAG 0x24
+#define SPRD_EFUSE_ERR_CLR 0x28
+#define SPRD_EFUSE_MAGIC_NUM 0x2c
+#define SPRD_EFUSE_FW_CFG 0x50
+#define SPRD_EFUSE_PW_SWT 0x54
+#define SPRD_EFUSE_MEM(val) (0x1000 + ((val) << 2))
+
+#define SPRD_EFUSE_VDD_EN BIT(0)
+#define SPRD_EFUSE_AUTO_CHECK_EN BIT(1)
+#define SPRD_EFUSE_DOUBLE_EN BIT(2)
+#define SPRD_EFUSE_MARGIN_RD_EN BIT(3)
+#define SPRD_EFUSE_LOCK_WR_EN BIT(4)
+
+#define SPRD_EFUSE_ERR_CLR_MASK GENMASK(13, 0)
+
+#define SPRD_EFUSE_ENK1_ON BIT(0)
+#define SPRD_EFUSE_ENK2_ON BIT(1)
+#define SPRD_EFUSE_PROG_EN BIT(2)
+
+#define SPRD_EFUSE_MAGIC_NUMBER 0x8810
+
+/* Block width (bytes) definitions */
+#define SPRD_EFUSE_BLOCK_WIDTH 4
+
+/*
+ * The Spreadtrum AP efuse contains 2 parts: normal efuse and secure efuse,
+ * and we can only access the normal efuse in kernel. So define the normal
+ * block offset index and normal block numbers.
+ */
+#define SPRD_EFUSE_NORMAL_BLOCK_NUMS 24
+#define SPRD_EFUSE_NORMAL_BLOCK_OFFSET 72
+
+/* Timeout (ms) for the trylock of hardware spinlocks */
+#define SPRD_EFUSE_HWLOCK_TIMEOUT 5000
+
+/*
+ * Since different Spreadtrum SoC chip can have different normal block numbers
+ * and offset. And some SoC can support block double feature, which means
+ * when reading or writing data to efuse memory, the controller can save double
+ * data in case one data become incorrect after a long period.
+ *
+ * Thus we should save them in the device data structure.
+ */
+struct sprd_efuse_variant_data {
+ u32 blk_nums;
+ u32 blk_offset;
+ bool blk_double;
+};
+
+struct sprd_efuse {
+ struct device *dev;
+ struct clk *clk;
+ struct hwspinlock *hwlock;
+ struct mutex mutex;
+ void __iomem *base;
+ const struct sprd_efuse_variant_data *data;
+};
+
+static const struct sprd_efuse_variant_data ums312_data = {
+ .blk_nums = SPRD_EFUSE_NORMAL_BLOCK_NUMS,
+ .blk_offset = SPRD_EFUSE_NORMAL_BLOCK_OFFSET,
+ .blk_double = false,
+};
+
+/*
+ * On Spreadtrum platform, we have multi-subsystems will access the unique
+ * efuse controller, so we need one hardware spinlock to synchronize between
+ * the multiple subsystems.
+ */
+static int sprd_efuse_lock(struct sprd_efuse *efuse)
+{
+ int ret;
+
+ mutex_lock(&efuse->mutex);
+
+ ret = hwspin_lock_timeout_raw(efuse->hwlock,
+ SPRD_EFUSE_HWLOCK_TIMEOUT);
+ if (ret) {
+ dev_err(efuse->dev, "timeout get the hwspinlock\n");
+ mutex_unlock(&efuse->mutex);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void sprd_efuse_unlock(struct sprd_efuse *efuse)
+{
+ hwspin_unlock_raw(efuse->hwlock);
+ mutex_unlock(&efuse->mutex);
+}
+
+static void sprd_efuse_set_prog_power(struct sprd_efuse *efuse, bool en)
+{
+ u32 val = readl(efuse->base + SPRD_EFUSE_PW_SWT);
+
+ if (en)
+ val &= ~SPRD_EFUSE_ENK2_ON;
+ else
+ val &= ~SPRD_EFUSE_ENK1_ON;
+
+ writel(val, efuse->base + SPRD_EFUSE_PW_SWT);
+
+ /* Open or close efuse power need wait 1000us to make power stable. */
+ usleep_range(1000, 1200);
+
+ if (en)
+ val |= SPRD_EFUSE_ENK1_ON;
+ else
+ val |= SPRD_EFUSE_ENK2_ON;
+
+ writel(val, efuse->base + SPRD_EFUSE_PW_SWT);
+
+ /* Open or close efuse power need wait 1000us to make power stable. */
+ usleep_range(1000, 1200);
+}
+
+static void sprd_efuse_set_read_power(struct sprd_efuse *efuse, bool en)
+{
+ u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE);
+
+ if (en)
+ val |= SPRD_EFUSE_VDD_EN;
+ else
+ val &= ~SPRD_EFUSE_VDD_EN;
+
+ writel(val, efuse->base + SPRD_EFUSE_ENABLE);
+
+ /* Open or close efuse power need wait 1000us to make power stable. */
+ usleep_range(1000, 1200);
+}
+
+static void sprd_efuse_set_prog_lock(struct sprd_efuse *efuse, bool en)
+{
+ u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE);
+
+ if (en)
+ val |= SPRD_EFUSE_LOCK_WR_EN;
+ else
+ val &= ~SPRD_EFUSE_LOCK_WR_EN;
+
+ writel(val, efuse->base + SPRD_EFUSE_ENABLE);
+}
+
+static void sprd_efuse_set_auto_check(struct sprd_efuse *efuse, bool en)
+{
+ u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE);
+
+ if (en)
+ val |= SPRD_EFUSE_AUTO_CHECK_EN;
+ else
+ val &= ~SPRD_EFUSE_AUTO_CHECK_EN;
+
+ writel(val, efuse->base + SPRD_EFUSE_ENABLE);
+}
+
+static void sprd_efuse_set_data_double(struct sprd_efuse *efuse, bool en)
+{
+ u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE);
+
+ if (en)
+ val |= SPRD_EFUSE_DOUBLE_EN;
+ else
+ val &= ~SPRD_EFUSE_DOUBLE_EN;
+
+ writel(val, efuse->base + SPRD_EFUSE_ENABLE);
+}
+
+static void sprd_efuse_set_prog_en(struct sprd_efuse *efuse, bool en)
+{
+ u32 val = readl(efuse->base + SPRD_EFUSE_PW_SWT);
+
+ if (en)
+ val |= SPRD_EFUSE_PROG_EN;
+ else
+ val &= ~SPRD_EFUSE_PROG_EN;
+
+ writel(val, efuse->base + SPRD_EFUSE_PW_SWT);
+}
+
+static int sprd_efuse_raw_prog(struct sprd_efuse *efuse, u32 blk, bool doub,
+ bool lock, u32 *data)
+{
+ u32 status;
+ int ret = 0;
+
+ /*
+ * We need set the correct magic number before writing the efuse to
+ * allow programming, and block other programming until we clear the
+ * magic number.
+ */
+ writel(SPRD_EFUSE_MAGIC_NUMBER,
+ efuse->base + SPRD_EFUSE_MAGIC_NUM);
+
+ /*
+ * Power on the efuse, enable programme and enable double data
+ * if asked.
+ */
+ sprd_efuse_set_prog_power(efuse, true);
+ sprd_efuse_set_prog_en(efuse, true);
+ sprd_efuse_set_data_double(efuse, doub);
+
+ /*
+ * Enable the auto-check function to validate if the programming is
+ * successful.
+ */
+ sprd_efuse_set_auto_check(efuse, true);
+
+ writel(*data, efuse->base + SPRD_EFUSE_MEM(blk));
+
+ /* Disable auto-check and data double after programming */
+ sprd_efuse_set_auto_check(efuse, false);
+ sprd_efuse_set_data_double(efuse, false);
+
+ /*
+ * Check the efuse error status, if the programming is successful,
+ * we should lock this efuse block to avoid programming again.
+ */
+ status = readl(efuse->base + SPRD_EFUSE_ERR_FLAG);
+ if (status) {
+ dev_err(efuse->dev,
+ "write error status %d of block %d\n", ret, blk);
+
+ writel(SPRD_EFUSE_ERR_CLR_MASK,
+ efuse->base + SPRD_EFUSE_ERR_CLR);
+ ret = -EBUSY;
+ } else {
+ sprd_efuse_set_prog_lock(efuse, lock);
+ writel(*data, efuse->base + SPRD_EFUSE_MEM(blk));
+ sprd_efuse_set_prog_lock(efuse, false);
+ }
+
+ sprd_efuse_set_prog_power(efuse, false);
+ writel(0, efuse->base + SPRD_EFUSE_MAGIC_NUM);
+
+ return ret;
+}
+
+static int sprd_efuse_raw_read(struct sprd_efuse *efuse, int blk, u32 *val,
+ bool doub)
+{
+ u32 status;
+
+ /*
+ * Need power on the efuse before reading data from efuse, and will
+ * power off the efuse after reading process.
+ */
+ sprd_efuse_set_read_power(efuse, true);
+
+ /* Enable double data if asked */
+ sprd_efuse_set_data_double(efuse, doub);
+
+ /* Start to read data from efuse block */
+ *val = readl(efuse->base + SPRD_EFUSE_MEM(blk));
+
+ /* Disable double data */
+ sprd_efuse_set_data_double(efuse, false);
+
+ /* Power off the efuse */
+ sprd_efuse_set_read_power(efuse, false);
+
+ /*
+ * Check the efuse error status and clear them if there are some
+ * errors occurred.
+ */
+ status = readl(efuse->base + SPRD_EFUSE_ERR_FLAG);
+ if (status) {
+ dev_err(efuse->dev,
+ "read error status %d of block %d\n", status, blk);
+
+ writel(SPRD_EFUSE_ERR_CLR_MASK,
+ efuse->base + SPRD_EFUSE_ERR_CLR);
+ return -EBUSY;
+ }
+
+ return 0;
+}
+
+static int sprd_efuse_read(void *context, u32 offset, void *val, size_t bytes)
+{
+ struct sprd_efuse *efuse = context;
+ bool blk_double = efuse->data->blk_double;
+ u32 index = offset / SPRD_EFUSE_BLOCK_WIDTH + efuse->data->blk_offset;
+ u32 blk_offset = (offset % SPRD_EFUSE_BLOCK_WIDTH) * BITS_PER_BYTE;
+ u32 data;
+ int ret;
+
+ ret = sprd_efuse_lock(efuse);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(efuse->clk);
+ if (ret)
+ goto unlock;
+
+ ret = sprd_efuse_raw_read(efuse, index, &data, blk_double);
+ if (!ret) {
+ data >>= blk_offset;
+ memcpy(val, &data, bytes);
+ }
+
+ clk_disable_unprepare(efuse->clk);
+
+unlock:
+ sprd_efuse_unlock(efuse);
+ return ret;
+}
+
+static int sprd_efuse_write(void *context, u32 offset, void *val, size_t bytes)
+{
+ struct sprd_efuse *efuse = context;
+ int ret;
+
+ ret = sprd_efuse_lock(efuse);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(efuse->clk);
+ if (ret)
+ goto unlock;
+
+ ret = sprd_efuse_raw_prog(efuse, offset, false, false, val);
+
+ clk_disable_unprepare(efuse->clk);
+
+unlock:
+ sprd_efuse_unlock(efuse);
+ return ret;
+}
+
+static int sprd_efuse_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct nvmem_device *nvmem;
+ struct nvmem_config econfig = { };
+ struct sprd_efuse *efuse;
+ const struct sprd_efuse_variant_data *pdata;
+ int ret;
+
+ pdata = of_device_get_match_data(&pdev->dev);
+ if (!pdata) {
+ dev_err(&pdev->dev, "No matching driver data found\n");
+ return -EINVAL;
+ }
+
+ efuse = devm_kzalloc(&pdev->dev, sizeof(*efuse), GFP_KERNEL);
+ if (!efuse)
+ return -ENOMEM;
+
+ efuse->base = devm_platform_ioremap_resource(pdev, 0);
+ if (!efuse->base)
+ return -ENOMEM;
+
+ ret = of_hwspin_lock_get_id(np, 0);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to get hwlock id\n");
+ return ret;
+ }
+
+ efuse->hwlock = devm_hwspin_lock_request_specific(&pdev->dev, ret);
+ if (!efuse->hwlock) {
+ dev_err(&pdev->dev, "failed to request hwlock\n");
+ return -ENXIO;
+ }
+
+ efuse->clk = devm_clk_get(&pdev->dev, "enable");
+ if (IS_ERR(efuse->clk)) {
+ dev_err(&pdev->dev, "failed to get enable clock\n");
+ return PTR_ERR(efuse->clk);
+ }
+
+ mutex_init(&efuse->mutex);
+ efuse->dev = &pdev->dev;
+ efuse->data = pdata;
+
+ econfig.stride = 1;
+ econfig.word_size = 1;
+ econfig.read_only = false;
+ econfig.name = "sprd-efuse";
+ econfig.size = efuse->data->blk_nums * SPRD_EFUSE_BLOCK_WIDTH;
+ econfig.reg_read = sprd_efuse_read;
+ econfig.reg_write = sprd_efuse_write;
+ econfig.priv = efuse;
+ econfig.dev = &pdev->dev;
+ nvmem = devm_nvmem_register(&pdev->dev, &econfig);
+ if (IS_ERR(nvmem)) {
+ dev_err(&pdev->dev, "failed to register nvmem\n");
+ return PTR_ERR(nvmem);
+ }
+
+ return 0;
+}
+
+static const struct of_device_id sprd_efuse_of_match[] = {
+ { .compatible = "sprd,ums312-efuse", .data = &ums312_data },
+ { }
+};
+
+static struct platform_driver sprd_efuse_driver = {
+ .probe = sprd_efuse_probe,
+ .driver = {
+ .name = "sprd-efuse",
+ .of_match_table = sprd_efuse_of_match,
+ },
+};
+
+module_platform_driver(sprd_efuse_driver);
+
+MODULE_AUTHOR("Freeman Liu <freeman.liu@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Spreadtrum AP efuse driver");
+MODULE_LICENSE("GPL v2");
--
1.7.9.5
